1. Field of the Invention
The present invention relates to a personal navigation terminal, and more particularly to an apparatus and a method for route guidance, which display routes by taking into consideration user preference for road structures, means of public transport, etc., in a personal navigation terminal.
2. Description of the Related Art
A Personal Navigation System (PNS) provides a location based service to Personal Digital Assistant (PDAs) or cell phones. Current location based service has been developed for a Car Navigation System (CNS) associated with vehicles. A PNS was developed by applying the location based service to a portable terminal for personal use.
Typically, a terminal for supporting a PNS is called a personal navigation terminal. A personal navigation terminal may be used inside a car while traveling as well as on a narrow sidewalk other than a roadway, alley, etc. A personal navigation terminal may also display a current location on a map. A personal navigation terminal may also display a map of an area around the current location, simultaneously shows the shortest distance route to a desired destination, etc., thereby providing users with various location information.
Such a PNS is similar to a CNS only in terms of displaying routes to a user. However, the CNS displays routes only for a roadway while the PNS displays routes along which a person can walk. Accordingly, the PNS needs a route guidance scheme different from that of the CNS. For example, when a driver travels to a destination, the CNS allows the driver to select a favorite road from an express highway, a national highway, etc., or select preference for a toll road. Further, the CNS uses a scheme for computing a route to the destination after reviewing the preference. However, in the PNS, the user preference must be differently reviewed.
For example, in the CNS, because the individual does not directly walk along an uphill road or a downhill road but moves along the uphill road or the downhill road by car, it is not necessary to consider the user's characteristics, fatigue, etc. However, in the PNS, because the individual is actually walking, it is necessary to consider the user's characteristics, fatigue, etc. When the individual continues to pass through underpasses or overpass viaducts in a city having many underpasses or viaducts, the individual may become very tired. Further, when the individual passes through a building construction zone, etc., the individual may suffer from strong noise and may be in danger.
However, the personal navigation terminal according to the prior art displays only the shortest route without taking into consideration the user's preferences based on users' characteristics, fatigue, etc. That is, the personal navigation terminal according to the prior art displays the shortest route including an uphill road even though a user cannot go up the uphill road. Further, when a user is disabled and cannot use a viaduct, an underpass interval or an uphill interval, the PNS according to the prior art displays only the shortest route without considering the user's characteristics.
In the PNS according to the prior art as described above, a user must receive the shortest route even if the shortest route is a road which the user does not want, a difficult road to walk or a road along which the user cannot pass through due to obstacles.